1. Field of the Invention
In general, the present invention relates to anatomy teaching aids. More specifically, the present invention relates to teaching aids designed to help teach the proper techniques for subdermal injections.
2. Description of the Prior Art
Physicians make injections under the skin of a patient for a great many reasons. For instance, if a physician is injecting a medication into a patient's bloodstream, the physician may insert a hypodermic needle directly into a vein. If a physician is trying to numb an area of the body, a physician may inject an anesthetic agent into tissue surrounding a particular nerve. Still in other applications, a surgeon may inject inert material, such as collagen, into fatty tissue under the skin to achieve a cosmetic effect.
Making an injection into a limb is a relatively simple procedure that is learned by first year medical students. The positions of the veins, arteries, muscles and nerves in the various limbs are well known and vary little from patient to patient. Although most medical personnel learn limb injection techniques by directly injecting patients, some training devices do exist. The training devices are typically plastic and rubber models of a limb, such as an arm. The training devices are used to learn the anatomy of a limb and to practice the location and depth of different injections. Such limb injection training devices are exemplified by U.S. Pat. No. 3,722,108 to Chase, entitled Injection Training Aid, and U.S. Pat. No. 3,789,518 to Chase, entitled Simulated Human Limb.
Making injections into the torso of a body are far more complex than those made in a limb. If an injection into a core part of the body is not precise, the needle may fail to reach the targeted tissue. Of more concern, an over-inserted needle or a misguided needle may puncture an internal organ or blood conduit, thereby causing internal bleeding. Physicians typically learn body core injection techniques while under close guidance by an experienced physician and/or practice on a cadaver. Training devices exist for developing the most rudimentary levels of experience. These training devices are little more than dummies with organ location maps attached to the outside of the body. Such prior art training devices are exemplified by U.S. Pat. No. 5,411,437 to Weber, entitled Medical Training Aid.
Perhaps the most difficult places on the body to practice and learn proper injection techniques is on the face and head. The skin and muscles on the face and head are very thin. Accordingly, the dermis and subcutaneous tissue layer are thin and hard to differentiate. Injections are further complicated by the complex contours of the face and head. Furthermore, a great many nerves and blood vessels run through the face and head. This anatomy also varies significantly depending upon the facial features of the patient.
In the practice of cosmetic surgery, a physician must make numerous injections to the face. Injections are made to either numb the face for a procedure or introduce a beneficial compound, such as collagen or Botox® under the skin. Physicians who practice cosmetic surgery cannot learn by trial and error on real patients. Likewise, practice on cadavers only has limited benefit because a cadaver lacks the skin resiliency and muscle suppleness of living tissue. Physicians must therefore learn from observation of other skilled physicians or by injecting models of fake skin. Models of fake skin are trays of simulated skin material into which a physician can practice injections. Such prior art practice devices are exemplified by U.S. Pat. No. 4,481,001 to Graham, entitled Human Skin Model For Intradermal Injection Demonstration Or Training. However, such injection practice devices are flat and do not teach a physician how to deal with the contours of the face or the anatomy present below the skin across the face.
A need therefore exists for a teaching aid for plastic surgeons and cosmetic surgeons that accurately models the face and head so that the physician can practice and learn injection techniques for these anatomical areas. This need is met by the present invention as described and claimed below.